Tuesday, 8 August 2017

Gemstones of Colorado

Colorado has more than thirty different varieties of gemstone. The official state gemstone is aquamarine, mostly found around 13,000 feet above sea level on Mount Antero. Other gem-quality minerals that have been found in Colorado include amazonite, garnet, topaz, tourmaline, lapis lazuli, quartz crystal, smoky and rose quartz, amethyst, turquoise, peridot, sapphire, and zircon.

Mount Antero

Agate, chalcedony, and jasper are found in many places. Amazonite is a variety of microcline feldspar. It is usually blue or green. Colorado amazonite is special because it can appear as well-formed crystals, as opposed to the formless shapes found elsewhere in the world. The crystals can also be very large.

Much of Colorado's amazonite can be found in the Pikes Peak granite. The granite provides the lead inclusions that color the microcline blue instead of pink. The Crystal Peak area between Woodland Park and Lake George is famous for its amazonite and other crystals, but it is now mostly private land and cannot be hunted.

Amazonite and Smoky Quartz, Copper

Among Colorado minerals that generate a high dollar volume are varieties of cryptocrystalline quartz. In its various forms, this mineral is known as carnelian, chalcedony, onyx, sardonyx, chrysoprase, agate, jasper, petrified wood and many others.

It is found in many locations around the state, with petrified (agatized) wood occurrences in Arapahoe, Douglas, Elbert, Delta, and El Paso counties.